This invention relates to the packing assembly of preformed anti-personnel or anti-material fragments known as flechettes for use in munitions fired from gun systems, delivered by rocket warheads, aircraft delivered bomblets.
In application it has been shown historically that ammunition designed for the distribution of preformed fragments have been more effective against personnel and materials than explosive munitions dependant upon shell casing fragmentation for effectiveness. Typically this type of artillery munition consisted of thin walled frangible shells which were randomly filled with spherical shot and fired directly at a target, and were the predominate type used for hundreds of years.
An improvement in the art was the invention of the spherical case shot by British Lieutenant Henry Shrapnel, which was adopted by the British military in 1852, and there evolved into the “shrapnel shell”. This shell used spherical shot having flattened surfaces to align the packing. They were propelled from within the non-fragmenting shell body by a base explosive charge ignited by a time fuse when the shell was in the proximity of the target. It allowed an improved and more effective distribution of the preformed fragments in indirect artillery fire against distant targets.
A further improvement in the art was seen in U.S. Pat. No. 2,767,656 R. J. Zeamer in which the spherical shot was replaced with cylindrical slugs in closely arranged and stacked in self supporting vertical columns within a semi-frangible shell casing having a predefined release control. This was an improvement over similar munitions using spherical shot for target saturation with preformed fragments, but it lacked effectiveness in long-range applications.
An further improvement in the art was seen in the U.S. Pat. No. 3,956,990 John F. Rose in which the munition consisted of preformed fragments consisting of small finned darts, known in the art as flechettes, being assembled in round clusters and stacked within a semi-frangible shell body in layers separated by metallic disks and support rings. A base exploding charge activated by a fuse when the shell was in the proximity to the target dispenses the flechette clusters and support assemblies. This type of flechette packing has been the conventional standard for artillery and rocket munition use since it's invention.
An object of the present invention is to provide an elimination of several of the drawbacks in the prior art flechette packing, which include: generally complicated assembly techniques; a multitude of supporting assembly components which aerodynamically interfere with the distribution of flechettes upon release from the shell body, creating a wider than wanted dispersal area and reduced target saturation; Internal lateral rotation and axial movements of the flechette packing and supporting assembly components due to voids, causing unwanted gyroscopic effects that influences precision guidance; and the physical distortion and deformation upon the material body and fins of the prior art flechettes that resulting from the inertial setback forces developed during firing from conventional and high velocity gun systems.